Turbochargers may be used in an engine system to increase a pressure of air supplied to the engine for combustion. In one example, the turbocharger includes a turbine coupled in an exhaust passage of the engine which at least partially drives a compressor via a shaft to increase the intake air pressure. During operation, turbochargers may become imbalanced, thereby displaying high levels of vibration and large variations in oil pressure within an oil cavity surrounding the turbocharger shaft. If the imbalance and vibration continues without servicing, severe turbocharger degradation and/or failure may result. For example, if the imbalance increases above a threshold, the turbocharger may fail within a period of time. In one example, the threshold may include a threshold change in vibration levels or oil pressure within a threshold frequency range.